Right to remove mouse’s head from trap (4)
I believe the answer is:
oral
'from trap' is the definition.
(trap informally can mean someone's mouth)
I cannot understand how the rest of the clue works.
(Other definitions for oral that I've seen before include "Spoken - examination" , "Relating to speech" , "By word of mouth, say exam" , "Relating to the mouth - exam" , "Spoken test" .)